Cutter-head.



He l.. FISHER.

CUTTER HEAD.

APPLICATIUN FILED AuG.|3. 19:3.

lygymr, Patented; @66.251,1918,

2 SHEETS-SHEET l.

H. L. FSHEE'l CUTTER HEAD.

APPLICATxoN .FILED AuG.13.1913.

Paented De@ 3L 1918.

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HENRY L. FISHER, 0F WAYNESBORO, PENNSYLVANIA, ASSIGNOR TO LANDIS MACHINE Q0., OF WAYNESBORO, PENNSYLVANIA, A CORPORATION 0F PENNSYLVANIA.

CUTTER-HEAD.

Specification of Letters Patent.

Parenteel nee. 3i, reis.

Application led August 13, 1813. Serial No. 784,656.

To all whom it may concern:

Be it known that I, HENRY L. FISHER, a citizen of the United States, residing at Waynesboro, Franklin county, and State of Pennsylvania, have invented and discovered certain new and useful Improvements in Cutter-Heads, of which the following .is a specification."

My said invention consists in an improved construction of cutter-heads for cutting threads on cylindrical bodies, it being especially designed for use in cutting threads on tubes or pipes, a leading purpose of the invention being to provide such a head whereby such work may be accomplished without danger of crushing or injuring the pipe and also wherein all sizes of pipe within the range of the cutter-head may be threaded with the same set of chasers, and various other advantages secured, all as will be hereinafter more fully described and claimed.

Referring to the accompanying drawings, I.

which are made a part hereof, and on which silnilar reference characters indicate similar parts,

Figure l is a face view of cutter-head constructed in accordance with my said invention,

Fig. 2 an edge View thereof,

Fig. 3 a plan view of the cam ring for adjusting the chaser holders,

Fig. f1 a central section through said ring on the dotted line 4 4 in Fig. 3,

Fig. 5 a detail edge view as seen from the dotted line 5-5 in Fig. 1,

' Fig. 6 a detail section on the dotted .line 6 6 in Fig. 1, and A Fig. 7 a detail section on dotted line 7 -7 in 'Fig 1.

In said drawings the portions marked A represent the body of the head, B the cam ring, and C the chaser holders.

The body comprises a cylindrical casting having a projection a on its rear side for attachment to the machine and with a radial lug 0r projection 10 on one edge to which the operating lever 11 is pivoted. It

is formed with a central circular aperture.

The cam ring B is mounted onan annular shoulder (see Fig. 1) on the face of body A and held thereon by a retaining ring 12 which is secured to the face of the body A by means of numerous cap screws 13, as best shown in Figs.- 1 and 6 and 7. The inner peripheral edge of the cam ring B is out away to. form an annular ledge that receives a corresponding portion formed on the retaining ring 12, and said' rings (B and 12) have a Hush face presented to the work. Said cam ring is formed with a cam slot, or groove 14, for each cutter holding slide, which slot extends across the slide, as best indicated in Fig. 1. A sliding block 15 is mounted in each of said cam slots.`

The cutter, Aor 'chaser, holding slides C are of the form best shown in Figs. 1 and 6 and consist of a long Ibase having dovetailed shaped tongues t onv their backs. Said slides are adapted to be mounted and slide in the tangentially positioned ways w in the face of the body A. Said ways w are preferably formed with central groove 16 of a shape in cross section corresponding to the tongues t which fit and slide therein. The inner ends of said slides are formed with axially projecting supporting heads o on which the chasers C1 are secured by clamping screws 17 and clamping plates 18 and 19.

Each cutter slide C is provided with a pin 2O projecting from its face adapted to engage an aperture inv the `sliding block 15 in the cam groove 14 of the ring B which lies across the path of said cutter slide. Said cam ring B is formed with a radial projection 21 on one edge having a curved slot 22 in which a stud or bolt 23 is adjustably secured.

The operating lever 11 is in the form of a bell-crank pivoted at its angle on a pivot 24. on the projecting ear 10- of the body A and its other arm is connected by a toggle joint 25 with said adjustable stud 23.

By means of said toggle the movement of.

to release the work. By adjusting the stud 23 in the slot 22, of the projection 21 on cam ring B, it will be seen that the die may be set for any sized work within the limit of the size of the opening through the head. This adjustment 1s accomplished by merely loosening the nut on said stud and moving it .to the position desired, which will be regulated by the size of the work, and then securing said nut in position. The adjustment necessary to adapt the die for different sizes of work may be readily determined by the graduation marks onthe edge ofsaid parts, as shown in Fig. 5.

It will be noted that in the construction of head shown I have provided six chaser slidesand six chasers and in order to accommodate lthis number of slides and provide for the use thereon of the long chaser with cutting grooves extending longitudinally, the use of which is desirable because of its long life and ease with which itis adjusted and renewed, it is necessary to set said cutter slides in positions so that the adjacent slides will extend at angles to each other less than a right angle, and tangential to a circle the center of which isthe axis of the die. I

also form notches n in the sides of the cutter holders adjacent to the rear corner of the next holder so that when the die is closed to its' innermost limits, the various slides will be able to clear each other. By this means I am able to provide the larger number of cutters in the die than usual and to distribute them at more frequent intervals around the circumference of the work, thus especially adapting the die for large work' with the chasers following veach other at substantially the s ame intervals that they-would in a die of ordinary construction on small work. This is a great advantage in threading pipes of large diameters. Not only because of the close relationship of the successive cutters or chasers, but also because of the equal distribution of the strain upon the worl:` throughout its circumference in all directlons which serves to equalize the thrust of the cutters against the work and obviate the. danger of crushing lor disturbing the contour of said work, which is a common v trouble in the use of cutter heads of ordinary construction.

Having thus fully described my said invention, what I claim as new and desire to secure by Letters lPatent is:

1. A die-head for cutting screw-threads comprising a body having supports in its face for cutter-holding slides :which supports extend tangentially to a circle the center of which is the axis o the head, the adjacent supports being at angles to each other.

less than right angles, cutter-holding slides mounted to slide in said supports, each cutter-holder being` notched or recessed on one side to receive the corner of the adjacent holder when the die is closed', cutters mounted on the inner ends of said slides and extending at right angles to the direction of movement of said slides, and means vconnected with each of said slides for simultaneously adjusting them to open and close the die, substantially as set forth.

2. A cutter-head provided with a series of supports extending tangentially to a circle the center of which is the axis of thehead and adjacent supports being at angles less than right angles to eachother, cutter-holding slides mounted in said supports, each formed with a notch in one side to receive the corner of the adjacent holder when the die is closed, cutters mounted on the inner ends-of said slides extending at right angles to said supports, means for simultaneously adjusting the normal position of said cutters, and means for simultaneously opening andhclosing the die, substantially as `set fort 3. A cutter-head comprising a body hav- HENRY L. FISHER. [La] Witnesses BRICE CURRAN. J osEPmNE ROLLMAN. 

